(CNN) -- China has rejected a new report which claims it has broken a promise to improve its human rights situation and "betrayed the core values of the Olympics."

China has tightened security around Beijing ahead of next month's Olympic Games.

The report by Amnesty International, entitled The Olympics Countdown: Broken Promises, was released Tuesday and outlines particular areas of concern including the death penalty, detention without trial, the persecution of rights activists and the lack of media freedom.

According to Amnesty, China promised an improvement in human rights, media freedom and better provision in health and education. Instead, it says, Beijing has locked up, put under house arrest and forcibly removed individuals they believe may threaten the image of "stability" and "harmony" they want to present to the world during next month's games.

"By continuing to persecute and punish those who speak out for human rights, the Chinese authorities have lost sight of the promises they made when they were granted the Games seven years ago," Roseann Rife, Asia-Pacific Deputy Director at Amnesty International, said on the organization's Web site.

Foreign Ministry spokesman Liu Jianchao said: "We hope Amnesty can take off the tinted glasses it has worn for many years and see China in an objective way."

Elsewhere in the report, Amnesty welcomed China's move last year to restore the Supreme People's Court's role in approving death sentences. But it criticized the government, which says the number of executions has declined, for withholding data on death penalty cases.

International Olympic Committee (IOC) President, Jacques Rogge, recently claimed the IOC's 'quiet diplomacy' had led to several human rights reforms in China, including new regulations for foreign media.

Don't Miss

"We welcome the IOC's recognition of its role on human rights, but given the current reality, we are surprised at their confidence that foreign media will be able to report freely and that there will be no internet censorship," said Roseann Rife. Learn how China monitors the Internet »

Despite new media regulations that were supposed to allow for freer reporting for foreign journalists, Amnesty says they continue to be prevented from covering "sensitive issues", including talking to those who suffer human rights violations. It says foreign correspondents in China reported more than 250 instances of interference with their work since the start of last year.

The group also believes that local activists and journalists working on human rights issues in China are at particular risk of abuse during the Games.

One example given by Amnesty is housing rights activist Ye Guozhu, who continues to serve a four-year sentence for "picking quarrels and stirring up trouble" because of his opposition to the seizure and demolition of property to make way for new Olympic construction projects.

Ye Guozhu's prison sentence was due to expire on 26 July. Instead the Chinese authorities say, he will remain imprisoned until at least 1 October, after the end of the 2008 Olympic Games.